Sheet-metal shears.



0. DE W. WAGNER.

SHEET METAL SHEARS.

APPLIOATIOE FILED FBB.3,1909.

Patented Sept. 28, 1909.

Ila

UNITED srarge s CLINTON DE WITT WAGNE rn'r rr cn.

E, OF CEDAR RAPIDS, IOVV' SHEET-METAL SHEARS.

Specification of Letters Patent.

Patented Sept. 28, 1909.

Application filed February 3, 1909. Serial No. 475,935.

Y To all whom it may concern:

tain new and useful Improvements in Sheet- Metal Shears, of whichspecification. v This invention relates tovshears used for cutting sheetmetal, and more particularly the type of shears described in LettersPatcnt No. 801697, granted to me on October 10th, 1905.

In the patent above referred to the device was more especially adaptedfor the cutting of curved forms, such, for example. as are used in themanufacture of elbows for fun nace pipe and the like, and showed meansfor operating the shears from behind, that is to say, the shears werepushed forward by the operator.

This invention embraces among other improvements means for drawing theshears forward, whereby they are adapted to cut much heavier materialthan would be possible by pushing the shears forward by hand.

.The full nature of the invention will clearly appear from thedescription and claims following, reference being had to theaccompanyingdrawing in which- Figure l is a sectional view ofa deviceembodying my improvements in a line central to Fig. 2. Fig. 2 is a topview of the. shears detached from any actuating mechanism. Fig. 3 is afragmentary view illustrating the front end of the lower portion of theshears and a section of guide track adapted to cooperate therewith.

tn the main the shears themselves do not differ essentially from thosedescribed in said former patent, and may brielly bc described asfollows:-l and .2 are. the halves of a rectangular frame. near theforward end of which is mounted a pair of rotary cutters, 3 and 4respectively. 4' and (i are throats in the back parts of the frames.through which the. slit nnaterial may pass. thus permitting the entireshears to traverse a. sheet of metal of any width. To the bot.- tom ofthe frame 1 .are attached rollers 7, adapted to travel oh the top of awork bench or form. Near the front end of this part of the shears isalso mounted a pair of rollers S, on vertical axes 9, adapted tostraddle a vertical form or guide strip it). This guide, in the case. ofelbow work and the following is a the like, is necessarily curved, anuin iotlowing it the desired shapes are accurately cut by the rotarycutters trailing a little in the rear of said guide rollers. In practiceithas been found unnecessary to employ a double set of guide rollers infront, as was shown in said former patent, the single pair herein shownserving every practical purpose.

In said former patent. was shown a pair of short guide ribs to engage apair of rollers at the rear, similar to the guide rollers in front. Onepart of my improvement relates to this feature and is clearly shown inFi 1. Instead of the outlying guide ribs the single rib 10 is extendedupwardly at 10* and the guide rollers engaging therewith are setrelatively higher than the front guide rollers so that after passing theextension these rollers are entirely free from the guide and do notinterfere with the action of the shears. whether the guide be straightor curved. The purpose of this auxiliary guide is to insure accurateinitial alinement. it is very essential in starting the cut at the edgeof a sheetthat it be accurately placed, otherwise the shears will bemore or less crowded out of their proper place and the work beinaccurately cut. Once it is properly started. however, the shearsfollow the guide and cut the blank as true to proper shape as could be.done by ordinary hand shears. In the hands of a careful workman theauxiliary guide at the rear might be dispensed with, but for ordinaryuse it is desirable, for reasons above noted.

.\nother improvement refers to asupport for the sheet, just in advanceof the cutters. To insure the best. results it is desirable to supportthemetal just in advance of the cutters and at just such a height withreference to their cutting edges that the cut may be made clean andwithout any raggedness on either side. 'lhenature of this support 11 isshown in Fig. l and it will be seen to consist of a simple plate withslotted holes at 1') to take the bolts to bywhich it is fastened to thelower frame l. The upper end of the support. 14' turns inwardlytowardthe cutters and forms a. resting place for the sheets just inadvance thereof. The slotted bolt holes admit of accurate adjustment, sothat as the. cutters wear and are ground smaller in diameter thissupport. may be tan-respondingly lowered and the accurate placing of thesheet thereby insured.

bearings 18 attached to the bench 19 and material which is too long tobe cut by the tion with upper and lower f Another improvement refers tomeans whereby the shears may be drawn forward instead of being pushed.The attachment for this purpose consists of a simple loop or bracket 15which in practice may be of stout wire bent to suitable form andfastened to the front end of the frame by the bolts 13. To this loop maybe attached any suitable pulling device, such as small Wire cable 16,and this is preferably wound on a drum or Windlass 17, mounted torevolve in suitable turned by a eranklt). By this means the shears maybe operated to slit quite heavy material, and of practically any widthor length desired. In practice it is used mainly in slitting sheetslengthwise and in straight lines, and is found very' useful in soslitting ordinary squaring shears, the operation being performed bothmore rapidly and accurately than can ordinarily be done by means ofhand, shears.- It is also much more convenient, since the parent sheetmay be suitably clamped to the bench at the proper level, and thenwithout any marking, and by a mere turnil'ig of the crank, the sheet maybe slit to any desired width or length.

Having thus described my invention I claim 1. In a sheet metal shear,and in combinarames adapted to permit the sheet to pass through them atthe rear, a pair of rotary cutters mounted in said frames, supportingfoot rollers thereunde a pair of guide rollers near the front end, apair of guide rollers at the back end set higher than the forward pair,and a guide to be straddled by said rollers, the guide being provided atone end with an upward extension, or auxiliary short guide,substantially as described.

In a sheet metal shear having fran'ies adapted to permit the slitmaterial to pass entirely between them, and provided with a pair ofslitting cutters, an adjustable sheet support mounted in front of saidcutters, and suitable means for attaching it adjustably to the lowerframe.

In a sheet metal shear, and iii-combination with frames adapted topermit the slit material to pass entirely between them and slittingcutters mounted in said frames, a loop or the like attached to oneof'said frames, whereby the shears may be drawn across the sheet from infront.

4-. The combination of sheet metal shears, con'iprising frames adaptedto permit the sheet to pass entirely between them and provided with apair of slitting cutters, a loop or the like on oneof said frames, apulling device such as a cable or the like connecting therewith, and aWindlass adapted to draw the shears across a sheet substantiallyas'described.

In testimony whereof .I atlix my signature in presence of two witnesses.

Witnesses:

J. M. S'r. Jon's, Rom. S. ZULLINGER.

